Heart disease is still the #1 killer in the U.S., followed by cancer and chronic lower respiratory tract disease. “Heart disease” is a broad category; the primary killer is heart attacks.
Eating fish regularly seems to reduce your risk of heart attack. I favor the cold-water fatty fish like salmon, trout, herring, and sardines.
I quote the NYT:
“Numerous studies have found that people who eat fish on a regular basis are less likely to die of a heart attack than those who don’t eat it or eat it less than once a month, and a 2006 Harvard review concluded that eating one to two servings of fish rich in omega-3s every week cut the risk of dying of a heart attack by one-third.”